This specification discloses an improvement in method and apparatus for identifying at a remote position conductors in a multiconductor means having the conductors identified at one end. The improvement is characterized by sequentially stepping by control signals from the remote position a sequential stepping switch onto contacts to which the identified conductors at the one end are connected, until a specifically identified conductor is connected with the sequential stepping switch. Thereafter, an identifiable signal is put on the specifically identified conductor and the conductor carrying the signal at the remote position is identified. The invention is particularly described with respect to repairing a telephone cable, or reconnecting groups of wire pairs from one cable to another in a telephone line system. In such telephonic work, ordinarily, it is advantageous to employ a second sequential switching device in conjunction with the sequential stepping switch to be able to monitor a pair of conductors, or wires, and to thereafter check out each individual wire of the pair. Also, disclosed is a field monitor unit to assist the repairman in maintaining a record of the particular conductor onto which the sequential stepping switch has been actuated. Other aspects are also described; such as, a flip-flop mode of operation in which correlated pairs of wires in a multiwire cable are identified for immediate changing of wires in a group with consequent lessening of chance of error.
A control system features built in test equipment for wiring harness interface testing, i.e., testing critical wires leading to the system from external signal sources, for reducing maintenance costs and for insuring critical wire validity of line replacement units.
Detecting faults and identifying conductor parts multiconductor telephone cables is many times necessary in the maintenance of a telephone communication system. The disclosed method and apparatus for this purpose includes a tone generator for connection to a telepone conductor pair at a first location of a cable and a receiver unit having a frequency tunable amplifier, a signal detection pickup coil or probe, and a headset connected to the tunable amplifier for use at a remote cable location to detect tones imposed on the pair at the first location. The method utilizes a tone generator which has a nominal signal frequency for use at the first cable location in conjunction with a pair of cable wires. The receiving unit is temporarily coupled to the wires at the first location so that the amplifier may be tuned to the precise frequency generated by the tone producing device. The receiving unit is then carried to the remote cable position and the probe or pick-up coil is used to sense the presence of signals generated. Because the amplifier has been tuned to the precise frequency of the signal provided by the tone generator, even weak signals may be detected in the presence of considerable interference from external source. A threshold circuit is provided at the output of the tunable amplifier to enable rejection of low level interference signals and to further improve the resolution of the detection equipment.
A cable conductor identification apparatus is provided having an electrical power source sequentially connectable to each of predetermined number of conductors in a cable at a first terminal end and a readout device connectable to any selected one of the conductors at a second terminal end. The electrical power source includes a sequentially pulsed diode matrix formed with dual sets of inputs which provide a discrete number of pulses at each of a predetermined number of terminals that are each connected to a respective conductor of the cable. The readout device is responsive to the number of pulses that are received during a test cycle and operative to provide a readout indicative of the particular conductor to which it may be connected.
An apparatus and method for tracing jumpers in a wiring rack such as the main distributing frame of a telephone central office utilizes a sensor such as a magnetic core around cables accessing the frame. Sensors along respective horizontal and vertical divisions of the frame are interconnected by respective address wires to form a location matrix. An appropriate identification signal is applied to either the address wires sequentially or to the jumper to be traced and the jumper or address wires, respectively, are monitored to detect a signal induced thereon by the appropriate sensor responding to the indentification signal. The particular address wires having a signal thereon simultaneous with the particular jumper specify the location of the activated sensor and hence the location of the end of the jumper.
A testing and recording system is disclosed for determining and recording the cable pair-line equipment assignments in a telephone central office. Using a multipair shoe on the main frame appearances of the cable pair, an off-hook condition is simulated successively on each of a plurality of idle cable pairs. At the same time, the dial tone markers are monitored to determine which line equipment responds to the off-hook condition. If the off-hook test condition is of very brief duration and takes place during times of low central office traffic, there is a high probability that only one off-hook condition will occur during the test interval. If only one dial tone marker response occurs during this brief interval, the cable pair identification and line equipment identification are recorded to create a record of this assignment. Alternatively, a tone associated with each dial tone marker is detected to ascertain which marker responded to the simulated off-hook condition.
